AC4300WPT

I have an air purifier that has a hepa filter and a UV C bulb that sterilizes the air passing though it, like in hospitals. No ozone. Seems to work well, bought on Amazon. https://a.co/d/0gog59cP

In addition to the cleaning suggestions and talking to your landlord about the HVAC system needing service, I would get a couple of good HEPA air filters that you can run non-stop. I have 4 of these https://a.co/d/85daMOr and they do a great job of getting dust and debris out of the air before it can settle. It won’t solve the problem, but it will help. The filters are easy to change as well.

Look under the cabinets where the pipes come in and see if there’s gaps. I had an apartment years ago where the smell from the lower unit was coming in through there. They put some spray foam in to block it off and it helped immensely. I have germ guardian purifiers with pet filters that I’ve had for years and they help a lot with allergens and I also smoke cannabis and it helps with that too (I live in a house so it’s just me, but it helps circulate the air and get cooking smells and cat dander out of the air too).

With that in mind a germ guardian tower is probably the most affordable good option. Whatever you buy should have UVC light built in to degrade mycotoxins, “plasmawave” or “bipolar ionizer” is also an acceptable alternative just make sure it’s California CARB certified. Stay away from classic ionizer/ozone

They don't really work if you have an active infestation. Ive got 4 lg ones in an 800sq ft house and I swear they do almost nothing. We even have this electrostatic filter in the hvac and still I've get systems when the doors close or the AC goes on. I have 2x airmega 200s, germ guardian rated for 900 sq ft, coway with uv rated for 600 sq ft. 2 upstairs and one down. If I were you id try to build the biggest Rosenthal filter or several as they don't get down hall ways or around stairs, etc. The think I don't like is they really tank your electric bill and are very noisy, as they have to stay on high mode.

I used this national allergy website. I got the Dyson and the germ guardian. Honestly I don't think the Dyson is worth the money. https://www.natlallergy.com/

I have 4 cats and one LR3. I found that whenever i start to smell pee it’s because someone has peed somewhere that’s not the box. I have found those 2 spots so I know right where to look. Before I realized this was happening one of the spots the pee got into the hard wood floor. Thankfully I was able to get the smell out with natures miracle. The other spot he would pee was right on the side of the litter box and close to the floor so it would just run under. After the floor scare I put a plastic mat under the box and the pee doesn’t absorb into anything and I think that makes a super noticeable smell. We have gotten the peeing under control thankfully. I’m always paranoid about the smell, like I just notice it clean or not. I put a purifier in the room with the box and I don’t even notice it anymore. I think the purifier is like a germ guardian or something. It works wonders.

The best bang for buck is germ guardian, and the parts are replaceable if something breaks. They sent us a replacement part for one of our units for free, no official warranty or anything. We have 3 of them that have been running for a decade in our house.

I have a germ guardian I bought in 2019 that I use in the room with a litter box and it significantly helps with the smell. I've used it before when my wife smoked up the kitchen trying to reverse sear a stream and it also helped a lot with the smoke. I know it's not one of the more suggested ones here but it's worked really well for me

Germ Guardian. Manual on/off switch that is connected to an alexa switch so I can turn them on and off on a schedule. One in every room. Alexa reminder every three months to buy and replace new filters